Apparatus for drying layer carriers



Oct. 29, 1963 w. LIMBERGER ETAL 3,108,863

APPARATUS FOR DRYING LAYER CARRIERS 2 Sheets- Sheet 1 Filed April 20, 1960 INVEN TORS-' Oct 29, 1963 w. LIMBERGER ETAL 3,108,863

APPARATUS FOR DRYING LAYER CARRIERS Filed April 20, 1960 2 Sheets-Sheet 2 United States Patent APPARATUS FQR DRYWG LAYER CR Waiter Limberger, Hamburg, and Georg Cranslrens,

Weds], Holstein, Germany, assignors to Lumoprmt Zindier KG, Hamburg, Germany Filed Apr. 29, 1960, Ser. No. 23,559 Claims priority, application Germany Apr. 25, 195 2 Claims. (Cl. 34155) This invention generally relates to an apparatus for drying layer carriers, and particularly to an apparatus for drying photographic layer carriers utilizing a guide element for said layer carriers which may be heated.

The invention shall be descibed according to a preferred embodiment of an apparatus for drying photographic layer carriers. In producing copies according to the diffusion method these layer carriers are ejected from a developing device in a wet state. The usual experience has been to hang up or to flatly place these layer carriers on a support until they had become dry. When drying the layer carriers tend to roll up so that the finished copy is wavy and must be pressed if required by high demands. This type of curling of the layer carriers will comm-only take place, as the layer carrier material has a different contraction coefficient than the layer material.

The main object of the invention is to provide an apparatus avoiding the aforementioned drawbacks in producing copies and shortening the total time required for producing the finished copies as well as improving the quality of the finished copies.

Another object of the invention is to provide an apparatus for the above mentioned purpose which may readily be adjusted to dilferent copy materials.

Another object of the invention is to provide an apparatus in which the passage of the layer carrier to be dried is facilitated at the same time avoiding the danger of sticking of the layer material to a roller. Besides this especially the output capacity shall be improved, as for example a metal roller is working at a temperature of 130 C. without objections, and the effectiveness of the apparatus may even be further improved by using higher temperatures.

These and other objects of the invention are accomplished in providing on either side of a layer carrier guide means comprising preferably at least one transport roller cooperating with said layer carrier and heating means for heating said guiding means to predetermined different temperatures. Preferably the arrangement at the layer carrier guide is so, that the layer side is heated more than the back side of the layer carrier.

According to a preferred embodiment of the invention each of the guide elements comprises at least one roller.

In a preferred construction the apparatus comprises a heating element for each of both guide elements which are substantially vertically arranged one below the other. In this construction the guide element, preferably a transport roller or a group of rollers, which may be heated to a higher temperature is arranged below the guide element cooperating with the other side of the layer carrier, which is also preferably a roller or a group of rollers.

Furthermore the invention provides for controlling the different heating of both guide elements, that the roller or group of rollers on one side of the layer carrier is supported movably in a direction towards said other roller or group of rollers and is, for example by a spring or a weight, urged in a direction towards the other roller. It is of advantage that between the rollers or group of rollers on the different sides of the layer carrier guide an adjustable gap is provided, which is preferably narrower than the thickness of the layer carrier. However, the invention also includes a construction according to 3 ,18,863 Patented Oct. 29, 1963 which the roller or group of rollers of both guide elements are contacting each other resiliently. In this case the conduction of heat between the rollers or group of rollers of the different guide elements is considerable so that the differences in temperature will be less than if an adjusted gap is provided. By means of this an especially simple construction of the apparatus is possible according to which it is possible to control the different heating of the guide element by providing only one heating element for both guide elements.

A preferred embodiment of the apparatus according to the invention provides an arrangement of the guide elements substantially one below the other within a chimney-like housing which the heating element for both guide elements is disposed below the lower guide element.

According to an especially advantageous embodiment at least one transport roller, preferably the one adjacent the layer side, is covered with a layer of material being indifferent to other materials yet showing a good resistance to heat. It is of advantage to cover both drying rollers with a layer of this type.

According to another preferred embodiment an adjustable shield is disposed between the heating element and the lower guide element. This shield preferably has in its fully adjusted position a wider shielding surface than the corresponding roller diameter.

Further advantages and features of the invention will become evident by the following description of one embodiment of the apparatus according to the invention g1ven by way of example only in connection with the accompanying drawings.

In the drawings is:

FIG. 1, a sectional side view of the apparatus accordmg to the invention, in which only those parts are shown which are essential for the functioning of the apparatus,

FIG. 2, a perspective view partly broken away showing FIG. 2a, schematically the arrangement of parts and, for illustrating further changed embodiments, additional elements, and

FIG. 3, a perspective view of details of the apparatus.

The apparatus shown in the drawings comprises a, a pair of substantially.

chimney-like housing 1 in which horizontally supported rollers 2 and 3 are arranged one below the other. The housing is kept relatively narrow, however a space being provided between its side walls and the rollers, said space preferably amounting to about the radius of the roller but being at least large enough that air may freely pass along the rollers.

In the illustrated embodiment the lower roller 2 is rotatably supported in said housing substantially horizontally but fixedly held in radial direction. The shaft of the lower roller is drivingly connected with a drive motor 4, rotating said roller 2 in the direction indicated by the arrow.

The shaft of the roller 3 is journalled adjustably in height. The ends of the shaft may for example be guided in elongated slots. The roller 3 is urged resiliently against the roller 2 by a spring or a weight in the direction indicated by the arrow 5. According to a preferred embodiment the guides for the ends of the shaft of the roller 3 are provided with adjustable abutments by means of which the end position of the roller 3 may be adjusted so that a narrow gap remains between the rollers 2 and 3. The abutment or the abutments on both ends of the shaft are for example adjustable by an adjustment screw providing the possibility that very fine adjustments may be made. The gap between the rollers should be narrower than the thickness of the layer carrier to be dried.

The rollers 2 and 3 are made of material having a good heat conductivity preferably metal. The rollers are for example made of copper, brass, or the like. The surface of the rollers is advantageously smoothly polished.

Although only one drive is shown in the illustrated embodiment it is also possible to drive both rollers for example by drivingly connecting the rollers by gears. In many cases howeverit will be sufiicient to drive the roller 2 only, as the other roller 3 will be rotated in the direction of the curved arrow by friction due to the pressure between the rollers. The drive of only one roller will particularly be sufficient if the rollers 2 and 3 are contacting each other. A drive of the roller 3 also is recommended if a gap is provided between the rollers, and whenever the apparatus is not operating constantly. In this case the upper roller would stand still during periods in which no layer carrier is fed causing it to be heated unevenly.

At the level of the roller gap opposing side walls of the housing have an inlet slot 6 and an outlet slot 7. To facilitate the feeding and passing of the layer carriers guide elements 8 and 9 in form of wire hoops are provided passing through the inlet and outlet slots and being bent back into the housing wall. By means of this on the one hand a neat looking feed opening diverging outwardly is provided with most simple means, and on the other hand an elastic pre-load of the guide elements 8' and 9 is achieved within the housing in such a way that the guide elements are pulled against the adjacent roller at the gap between the rollers. By means of this it is assured that the guide elements may follow a movement of for example the adjustable roller 3 but that they will return when the roller 2 is lifted off. Furthermore it is assured that, in the range of the roller gap in which the guide elements 8 and 9 are guided in circumferential grooves 1d and 11 of the rollers 2 and 3, merely the rollers 2 and 3 will act upon the layer carrier when the circumferential grooves 10 and 11 are advantageously made slightly deeper than the thickness of the guide elements 8 and 9. The elastic force of the guide elements is so as to not interfere with the movement of the roller 3 towards the roller 2 caused by the load of a weight or a spring.

Below the roller 2 within the housing a heating device 12 is disposed which, according to the preferred embodiment has a concave surface facing the lower roller. The heating device comprises several heating elements 13 which may either freely extend between supports arranged on the face walls of the housing or they may be imbedded within a suitable mass. Preferably electric heating elements are used.

The heating device 12 may be covered by a shield 14. This shield is bent upwardly and pivotally supported by two sector-like arms 15 for example at 17 on the face walls of the housing. The shield is shown in full lines in its shielding position over the heating device 12 which is substantially completely covered by the shield below the roller 2. The heated air however may pass-by the sides of the shield 14 within the housing and flow upwardly passing the sides of the rollers 2 and 3. By means of this a good heating of the air within the housing 1 is assured, even if the heating of the rollers 2 and 3 is to be throttled.

An opening 16 is provided in one of the side walls of the housing through which air is fed into the housing. This opening is fully open if the shield is in its described position. Hereby the air passage through the housing is increased whenever the heating of the rollers 2 and 3 is throttled, thus increasing the throttling effect.

If no shielding is desired the shield is pivoted into the position shown by the dashed lines in which position it covers a substantial part of the opening 16. Thereby the amount of air passed through the housing 1 is decreased. Due to the sector-like shape of the shield 14 and arms 15 however, also a downwardly open chimney-like draft opening for entering air is provided, if the shield is in the outwardly pivoted position.

Openings 18 are arranged in the upper wall of the housing serving as outlets for the air. These openings may for example also be made adjustable with respect to their cross sections by providing a screen or the like, so that the passage of air through the housing or the damming of hot air within the housing may be adjusted.

Furthermore FIG. 1 shows in dotted lines a possible bearing construction for the upper roller 3. The shaft of this roller is guided in a bearing block. This block may for example be made with two parallel, vertical sides which are slidingly guided on the edges of a vertical slot 48 provided in the wall of the housing. An abutment screw 5% may for example be adjustably arranged in a bracket 49 connected with the wall of the housing. This screw 50 is forming an abutment for the bearing block 47 and determines its lowermost position. A spring 51 is pressing on the top side of the bearing block, said spring being also preferably supported by a bracket 52 of the wall of housing. An arrangement like this is provided at both ends of the roller, so that the adjustment of a gap is possible, simultaneously allowing the roller to be lifted upwardly in a resilient manner.

Referring now to FIG. 2 it will be seen that at the same time several possibilities for embodying the inven tion are shown. With respect to the heating deviceand its shield FIG. 1 is referred to substantially.

On a base plate 19 two face wall-like supports 20, 21 are arranged serving to support two rollers 22, 23. Both ends of the roller shafts extend into corresponding hearing means of the walls 2% and 21. The roller 23 for example is merely journalled for free rotation, while the ends of the shaft 24 and 25 of the roller 22 are arranged in bearing blocks 26 which are slidingly guided in substantially vertically elongated slots 27 of the two walls 20 and 21. Above each of these bearing arrangements a projection 2-8 is provided on the side walls serving as abutrnents for a pressure spring 29' by means of which the roller 22 is urged. against the roller 23. The tension of the pressure spring 2? is adjustable by a screw 30.

The guide elements which according to FIG. 1 are extending through the circumferential grooves of the rollers, and which are connected with the not shown longitudinal walls of the housing near the edges of the inlet and outlet slots are not illustrated in FIG. 2. it is to be noted however that the use of these guide means is included. If therollers are provided with a layer thecircumferential grooves for the wire hoops forming the guide elements may readily be arranged by providing portions of layer disposed in spaced relation.

Below the roller arrangement the shield 31 is pivotally supported by the face wall-like supports 20 and 21. Not visible heating element-s 32 are arranged below the shield, shown in dashed lines. The shield cooperates with a slot in one of the side walls of the housing through which it may for example be pivoted by a lever 33 ex tending outwardly, and through which heat may be eliminated in dependence on theposition of the shield.

The rollers 22 and 23 are provided with layers 34 and 35 which for example may consist of plastic material or a corresponding material of good heat resistance and of indifferent characteristics with respect to other substances. The heat resistance must be high enough to withstand an operating temperature of. up to 200 C. at which the drying process may be carried out.

The choice of the layer material depends on the type of layer carriers to be dried or respectively the temperatures at which the layer carriers may be dried. The above mentioned range is preferred. According to the invention also higher temperatures may be used, if required. The layers on the rollers may have a thickness of for example 1 mm.

According to an especially advantageous embodiment a layer of plastic material is provided preferably using a highly molecular material such as polytetrailuorethylene (e.g. Teflon), polyfluorcarbons, silicones and polyamides. These plastic materials do not show any so-called active ends in their structure, which might cause adhering.

For example slight resiliency is provided for the layer. A special embodiment uses as a layer of at least one roller a foil of silicone-caoutchouc.

The invention also includes a rigid layer. According to this feature the surface of a metal roller is for example silicone plated by applying a solution of silicone, whereupon this solution is burned in.

According to an especially advantageous feature of the invention a layer is applied to the rollers made of good heat conducting material Within which apertures are provided. These apertures for example may have the form of round holes having a diameter of about 1-2 mm. which may be disposed in any way. The invention also includes other forms of apertures. Experience has shown that by the provision of holes the adhering effect especially on the layer side of the layer carrier is greatly decreased. This is caused by the fact that by providing holes air cushions are formed and, in addition to this, the enclosure of air is effecting an especially good drying effect.

In this embodiment the holes 36 and 37 are arranged sieve-like in the layers 34, 35 having a diameter of l2 mm. and being spaced from each other 2-3 mm, this dimension being taken from border to border of the holes. The invention is by no means limited to the dimensions stated for this preferred embodiment, as for example, greater distances between the holes and greater diameters may be used.

The round form of the holes is preferred, but also other regularly or irregularly shaped holes are included in the scope of the invention. In this connection especially a slot-like shape of the holes is pointed out, the holes being arranged so, that they will cross each other at the different rollers.

According to a special form of embodiment in certain patterns of the holes a drive connection for example in form of a gearing is arranged between the ends of the two roller shafts in order to obtain defined positions of the holes on both rollers with respect to each other. Such a gearing is illustrated by the gears 33 and 39 arranged on the end of the roller shafts. The gears are meshing with play, particularly with respect to the working depth to avoid interference of the movement when the upper roller is resiliently urged against the lower roller.

A drive motor 40 is for example mounted on the face wall-like support 21. It is pointed out however that a drive by means of a crank is possible and is included in the scope of the invention.

At the left side of the FIG. 2 a changed device for urging the two rollers together by a weight is shown. At a bearing 46 for the shaft of the upper vertically movable roller 22 a hairpin-like suspension 41 is fastened, through which the shaft of the lower roller is extending with play at both sides, and which serves to carry a weight 42 suspended from its lower end.

Within a box 43 the main feed terminals for feeding the heating elements are arranged. There is a possibility to provide control means within this box controlling and adjusting the heating elements. The adjusting means of this control may for example be a disc 44 projecting partly through a slot of the box 43.

It is for example also possible to avoid the shield 31 and the heating elements arranged thereunder by arranging separately controllable heating elements within each of the rollers 22 and 23. In this case the ends of the shafts of the rollers '22, 23 disposed on the side of the terminal box 43 are hollow shafts, through which the conductors 45, shown in dashed lines, are extended leading to the heating elements arranged within the rollers. The control may in this case be so that always a predetermined relation between the temperatures of the rollers is assured.

It is to be noted that also separate features and sub- 6 combinations without reference to other features and subcombinations are suitable. Therefore the utilization of separate features and subcombinations in accordance with the appended claims are within the scope of this invention. Futhermore it should be noted that changes of details are possible without departing from the scope of the invention. Therefore this invention shall by no means be restricted to the described and illustrated embodiment.

What we claim is:

1. An apparatus for heating layer carriers, particularly photographic layer carriers, comprising a housing having a pair of opposite side walls, inlet means for the layer carriers in one of said side walls, outlet means for the layer carriers in the opposite side wall at substantially the same level as said inlet means, air permeable guide means extending between said inlet means and said outlet means within said housing, a first horizontal transport roller rotatably mounted substantially below said guide means and extending transversely thereof, a second transport roller rotatably mounted substantially above said guide means and parallel with said first transport roller, said first and second transport rollers being made of material having good heat conductivity, means for rotating at least one of said transport rollers, heating means disposed below said first transport roller, an air admission opening in the lower portion of one of said side Walls, air discharge means in the top portion of said housing, means dofining a shield extending along and substantially parallel with said heating means, and means mounting said shield in the hous'mg for movement between a first position between said heating means and first transport roller and a second position in which the shield projects at least partly through said air admission opening and thereby at least partly closes said air admission opening.

2. An apparatus for heating layer carriers, particularly photographic layer carriers, comprising a housing having a pair of opposite side walls, inlet means for the layer carriers in one of said side walls, outlet means for the layer carriers in the opposite side wall at substantially the same level as said inlet means, air permeable guide means extending between said inlet means and said outlet means within said housing, a first horizontal transport roller rotatably mounted substantially below said guide means and extending transversely thereof, a second transport roller rotatably mounted substantially above said guide means and parallel with said first transport roller, said first and second transport rollers being made of material having good heat conductivity, a perforated resilient coating on said transport rollers comprising a silicone solution burnt into the surfaces thereof, means for rotating at least one of said transport rollers, heating means disposed below said first transport roller, an elongate shield extending along and substantially parallel with said heating means, means mounting said shield in the housing for movement between a firs-t position in which the shield substantially prevents direct heat radiation from the heating means to the transport rollers, and a second position in which such direct heat radiation is unobstructed, air admission means in the lower portion of said housing and at least partly below said heating means, and air discharge means in the top portion of said housing, said transport rollers and heating means being spaced from said side walls suflicient- 1y to cause said housing to function as an air chimney.

References Cited in the file of this patent UNITED STATES PATENTS 1,085,230 Wild at al Jan. 27, 1914 1,890,832 Von Hoessle Dec. 13, 1932 2,328,321 Berry Aug. 31, 1943 2,551,804 Marasco May 8, 1951 2,656,449 Elgar Oct. 20, 1953 2,679,572 Workman May 25, 1954 2,828,123 Guillemette Mar. 25, 1958 2,892,263 Hornbostel June 30, 1959 

1. AN APPARATUS FOR HEATING LAYER CARRIERS, PARTICULARLY PHOTOGRAPHIC LAYER CARRIERS, COMPRISING A HOUSING HAVING A PAIR OF OPPOSITE SIDE WALLS, INLET MEANS FOR THE LAYER CARRIERS IN ONE OF SAID SIDE WALLS, OUTLET MEANS FOR THE LAYER CARRIERS IN THE OPPOSITE SIDE WALL AT SUBSTANTIALLY THE SAME LEVEL AS SAID INLET MEANS, AIR PERMEABLE GUIDE MEANS EXTENDING BETWEEN SAID INLET MEANS AND SAID OUTLE TMEANS WITHIN SAID HOUSING, A FIRST HORIZONTAL TRANSPORT ROLLER ROTATABLY MOUNTED SUBSTANTIALLY BELOW SAID GUIDE MEANS AND EXTENDING TRRANSVERSELY THEREOF, A SECOND TRANSPORT ROLLER ROTATABLY MOUNTED SUBSTANTIALLY ABOVE SAID GUIDE MEANS AND PARALLEL WITH SAID FIRST TRANSPORT ROLLER, SAID FIRST AND SECOND TRANSPORT ROLLERS BEING MADE OF MATERIAL HAVING GOOD HEAT CONDUCTIVITY, MEANS FOR ROTATING AT LEAST ONE OF SAID TRANSPORT ROLLERS, HEATING MEANS DISPOSED BELOW SAID FIRST TRANSPORT ROLLER, AN AIR ADMISSION OPENING IN THE LOWER PORTION OF ONE OF SAID SIDE WALLS, AIR DISCHARGE MEANS IN THE TOP PORTION OF SAID HOURSING, MEANS DEFINING A SHIELD EXTENDING ALONG AND SUBSTANTIALLY PARALLEL WITH SAID HEATING MEANS, AND MEANS MOUNTING SAID SHIELD IN THE HOUSING FOR MOVEMENT BETWEEN A FIRST POSITION BETWEEN SAID HEATING MEANS AND FIRST TRANSPORT ROLLER AND A SECOND POSITION IN WHICH THE SHIELD PROJECTS AT LEAST PARTLY THROUGH SAID AIR ADMISSION OPENING AND THEREBY AT LEAST PARTLY CLOSES SAID AIR ADMISSION OPENING. 